Material working machine

ABSTRACT

A bank of individual working tools are selectively movable in response to movement of a cam means, the working tools being counterbalanced to regulate the pressure at which they engage a workpiece.

United States Patent 1 Schiller et al.

[ Dec. 11, 1973 Filed:

MATERIAL WORKING MACHINE Inventors: Jacob D. Schiller; Scott L. Cheslik,

both of Indianapolis; J. Tim Gonzales, Carmel, all of 1nd.

P. R. Mallory & Co., Inc., Indianapolis, 1nd.

Oct. 14, 1971 Appl. No.: 189,429

Assignee:

US. Cl. 219/87, 219/91 Int. Cl 323k 11/10 Field of Search 219/87, 86, 89, 91,

References Cited UNITED STATES PATENTS Roth 219/87 1,649,412 11/1927 2,521,471 9/1950 2,109,461 3/1938 3,393,287 7/1968 Hammond et a1. 219/87 X 1,850,454 3/1932 Gross 219/117 HD 2,678,367 5/1954 2,727,122 12/1955 3,504,156 3/1970 Primary Examiner-Bruce A. Reynolds Attorney-Richard H. Childress et a1.

[57] ABSTRACT A bank of individual working tools are selectively movable in response to movement of a cam means, the working tools being counterbalanced to regulate the pressure at which they engage a workpiece.

3 Claims, 4 Drawing Figures PATENIEDUEE 11975 SHEE? 1%? 2 1 MATERIAL WORKING MACHINE The present invention relates to metal working machinery. While the invention will be described with particular reference to metal working machinery, it should be understood that it will be applicable to various materials such as plastics.

Depending upon a particular application, metal working machinery may be constructed with multiple working heads. For example, it may be desirous to drill a series of holes in a sheet of metal. Under such circumstances, the metal working machinery usually includes a bank of individual drills which may either drill a series of holes simultaneously or in sequence. As another example, a series of spot welds may be made either simultaneously or in sequence through the use of a bank of individual electrodes. In the case of the welding apparatus, it would be preferable that the individual spot welds be made individually through sequential activation of the individual electrodes. By this method, very close spaced welds are possible with closer control of the desired weld pressure.

In welding, one method of sequentially forming a series of spot welds from a bank of electrodes is to selectively energize the electrodes with a workpiece in response to pneumatically operated pistons. Such a method, however, leads to inaccuracies in the timing sequence of the electrodes and in addition, leads to bulky and complicated equipment.

The present invention is concerned with a metal working machine wherein a series of operations are sequentially carried out from a bank of sequentially operated metal working tools and has as one of its objects the provision of such a machine which is simple and easy to produce.

Another object of the invention is the provision of a metal working machine having a bank of metal working tools which are sequentially operated in a positive, accurate manner.

Still another object of the invention is the provision of a metal working machine having a bank of individual metal working tools which are individually, selectively operated in accordance with the movement of a cam means.

' Still another object of the'invention is the provision of a metal working machine having a bank of individual cam operated metal working tools which are counterbalanced to regulate the pressure at which a working tool engages a workpiece.

Yet another object of the invention is the provision of a multiple electrode sequential welding apparatus which is sequentially operable from a cam means.

Another object of the invention is to provide a method of providing a plurality of spaced spot welds via electrical resistance welding by providing a bank of individual cam operated electrical welding electrodes to v sequentially engage a workpiece.

Another object of the invention is to provide a plurality of spaced spot welds via electrical resistance welding using a bank of sequentially operated electrodes with electrical power being supplied to the complete bank of electrodes by a single transformer with an electrical circuitbeing completed only through a single electrode performing a spot weld.

Yet still another object of the invention is to provide a method of providing a plurality of spaced spot welds by individually cam operated welding electrodes sequentially engaging a workpiece which are counterbalanced so as to allow the electrodes to engage the workpiece at a predetermined pressure.

These and other objects of the invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a front elevation of the apparatus of the present invention;

FIG. 2 is an end view of the apparatus;

FIG. 3 is a section taken along the line 33 of FIG. 1; and

FIG. 4 is a view taken along the line 44 of FIG. 3.

Generally speaking, the objects of the invention are accomplished by providing a metal working machine which, in general, comprises a cam means, a bank of individual metal working tools disposed in juxtaposition with respect to each other, each movable in response to movement of the cam means, and a platen disposed beneath the bank of the individual working tools. Movement of the cam means selectively moves individual metal working tools of the bank of tools into working relationship with a workpiece. In the illustrative embodiment of the invention, the metal working tools include electrodes such that a series of spot welds may selectively be made in response to the rotation of the cam means.

Referring now to the drawings, there is shown a metal working machine 10 employing the principles of the present invention. A pair of spaced upstanding support walls 12 and 14 are carried by a base member 16. A shaft 18 is fixedly carried by the support walls 12 and 14. A carriage means 20, which includes side bars 22 and 24 connected by an end bar 26, is pivotally carried by the shaft 18, the carriage being journalled on the shaft through sleeve 28 and bearings 30 and 30. Cam carrying shaft 32 is rotatably journalled in the carriage means 20 through bearings 34 and 34' so as to be freely rotatable therein. Cam carrying shaft 32 is power driven through a suitable drive motor (not shown) which is connected to the cam carrying shaft through belts 36 and 38 carried by pulleys 40, 42 and 44, pulleys 40 and 42 being rotatably journalled on shaft 18 and pulley 44 being fixedly carried by shaft 32.

A cam means 46 is carried by the shaft 32. Cam means 46 includes a bank of individual cams 45, the cam surfaces 47 of which are separated by rings 48. Each cam surface includes a single lobe or step 47 A second cam means 50 is also carried by the shaft 32.

Cam means 50 includes cams 52 and 54 carried by a hub 56. These cams operate microswitches 58 and 60. Cam 54 includes a number of lobes 54' corresponding to the number of working tools in a bank of working tools .to be described, while cam 52 includes a single lobe. Microswitches 58 and 60 are carried by frame 62 which is secured to carriage means 20.

Carriage means 20 rests on a support means 64 which includes a support bar 66 carried by the support walls 12 and 14 between the pivot point (shaft 18) and the end portion of the carriage means carrying shaft 32 and cam means 46. The carriage means 20 is counterbalanced through counterbalancing means 68 which includes a counterweight 70 carried by the end portion of the carriage means on the other side of the pivot point (shaft 18). counterweight 70 is carried by a plate 72 which extends across the side bars 22 and 24 of the carriage means.

A third shaft 74 is fixedly carried by support walls 12 and 14. A bank of individual cam follower arms 76 are pivotally carried on the shaft 74 between the opposed end portions 76 and 76" of the follower arms. Each of the follower arms are spring biased through springs 78 connected between the end portion 76" and base member 16. Rotation of cam means 46 pivots an individual follower arm in accordance with a particular cam, the cam surface biasing an arm through a circular disc 80 which is made of a hard, wear resistant material such as molybdenum. Disc 80 is securely held within the arm through a pin 82.

A bank of individual working tools 84 are carried by each individual follower arm 76 so as to be disposed in juxtaposition to each other. in the illustrative embodiment of the present invention, the metal working tools 84 include individual electrodes 86 each carried by a block 88 which is secured to arm 76 through bolts 90. Block 88 is electrically isolated from the follower arm 76 by a pad 89 of an electrically insulative material such as a paper base phenolic. Bolts 90 are electrically isolated from the arm through sleeves 91 and 93 which may also be fabricated from a paper base phenloic. As will become apparent, the working tools 84 are pivoted in response to the pivoting of the follower arms 76 which in turn is responsive to the rotation of the individual cams of the cam means 46. Electrical current is supplied to the individual electrodes from a power source (not shown) through cable 92 to a bussing bar means 94 and then to the individual electrodes through cables 96.

A platen 98 upon which a workpiece may be carried or which otherwise serves as a pressure base is pivotally carried by shafts 74. The platen is spring biased by a pair of springs 100 and 102 which are connected to the platen and base member 16. In the illustrative embodiment of the present invention, the platen includes a single electrode 104 disposed beneath the individual electrodes 86 and spaced therefrom and having a length extending along the length of the bank of electrodes. The single electrode is carried by a block 103 in laterally extending notch 101. Block 103 is bolted to bar 111 through bolts 95, bar 111 being secured to bar 105 through bolts 107. Bolts 107 also secure bar 105 to base 97. Bar 111 and thus block 103 is electrically isolated from bar 105 through pad 99 which may be fabricated from an electrically insulative material such as a paper base phenolic. By loosening lock screws 109, electrode 104 may be adjusted lengthwise within notch 101 when areas below individual electrodes 86 become worn. Vertical adjustment of block 103 is provided through the cooperation of set screws 113 and bolts 95. The platen pivots in response to actuator means 106 which includes a roller 108 carried by frame 110 and ramp 112 which is actuated by air cylinder 114. When air cylinder 114 is actuated, ramp 112 engages roller 108 to thus pivot the platen 98. When the platen is pivoted to its operating position, microswitch 116, which is connected to the platen through rod 117, is actuated to close a circuit to the motor driving the shaft 32. Electrical power is supplied to the electrode 104 through electrical cable 115.

For purposes of illustrating the operation of the device, there is shown a capacitor anode 118 having a riser 120 to which a lead wire 122 is to be welded. The riser and the lead wire are held in overlapping relation for welding to each other at or near area 124. The capacitor with its riser and the lead wire are fed between the electrodes 86 and the electrode 104 through some suitable means (not shown). After the anode and the wire 122 are properly positioned, platen 98 is pivoted into operating position such that the electrode 104 engages or is in very close proximity to the spot or area to be welded. Microswitch 116 is actuated to close a power circuit to the motor to drive or rotate shaft 32. Cam means 46 is then rotated such that a cam lobe 47 of the individual cams selectively engages individual follower arms 76 to bring an individual electrode 86 into engagement with the spot or area to be welded. Upon engagement of an electrode 86 with the spot to be welded, cam 54 through one of the lobes 54' trips microswitch 60 which closes an electrical circuit from a transformer (not shown) to apply an electrical potential across the complete bank of electrodes and electrode 104. An electrical circuit will be completed through a single electrode 86 which engages the spot to be welded. As electrode 86 engages the spot to be welded, carriage means 20 is lifted off support bar 66 such that counterbalancing means 68 will counterbalance the pressure at which the electrode 86 engages the spot to be welded to thus regulate the amount of pressure with which the electrode 86 engages the work.

When a complete series of spot welds is completed on a series of anode risers through selective engagement of an electrode 86 with the work, air cylinder 114 is again actuated to lower the platen away from the work and the single lobe of cam 52 engages normally closed microswitch 58 to open a circuit to the motor driving shaft 32 to stop its rotation.

We claim:

1. A welding machine comprising:

a. spaced support walls carried by a base member,

a first shaft fixedly carried by said support walls,

a support means carried by said support walls,

carriage means having opposed end portions pivotally carried on said first shaft between said end portions, one end portion of said carriage means resting on said support means,

e. a second shaft rotatably carried by said carriage means in said one end portion and a bank of individual cams coupled to said second shaft,

f. a counterweight carried by said carriage means at its other end portion,

g. a third shaft carried by said spaced support walls,

h. a bank of individual cam follower arms having opposed end portions each pivotally carried by said third shaft between said end portions, an end portion of each arm responsive to rotation of a cam of said bank of individual cams,

i. welding tools carried by said follower arms at said end portion responsive to said cam means,

j. spring means connected to said base member and the other end portion of each of said cam follower arms,

k. a platen having opposed end portions pivotally carried by said third shaft between said end portions, one end portion in spaced relation with said welding tools,

1. spring means connected to said base member and the other end portion of said platen, and

m. actuator means engaging and pivoting said platen into working relationship with said welding tools.

2. A material working machine according to claim 1 wherein said platen includes an electrode extending the length of said bank of individual welding electrodes.

3. A welding machine according to claim 1 wherein said actuator means includes a roller means connected v I INITED STATES ATENT OFFI E I CERTIFICATE OF CORRECTION 2 Patent No. l 3,778,582 I Dated December IL 1973 Inv ntms) 0.0 Schiller. s.L. Chesh'k'. and JLT. Gonzales It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown belowz 01 3, line 23 delete "phenloic" and insert ---phen011'c---.

C01. 3, Hne 34, delete "shafts" and insert ---shaft---.

Signed and sealed this 29th day of October 1971,

. (SEAL) Attesta McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM PO-IOSO (10-69) USCOMM'DC 60376-P69 fi U.S. GOVERNMENT PRINTING OFFICE: I969 O-366-33l UNITED STATES PATENT OFFICE;- v I CERTIFICATE OF CORRECTION Patent No. 3,778,582 Dated December 11, 1973 Inv n fl J.D Sch1'11er. S. L. Chesl-ikwand J T. Gpnza'les It is certified that error appears in the' aboveidentified patent and that said Letters Patent are hereby corrected as shown belowz C01 3, line 23 delete "phenloic" and insert ---phen011'c--,-.

"3 de1ete "shafts" and insert ---sha Signed and sealed this 29th day of October 1971,

.. '(SEAL) Attesta McCOY M. GIBSON JR. C'.'MARSHALL DANN Attesting Officer Commissioner of Patents FORM P040550 (10-69) I uscoMM-Dc 60376-P69 0.5. GOVERNMENT PRINTING OFFICE 1 199 0-366-33 

1. A welding machine comprising: a. spaced support walls carried by a base member, b. a first shaft fixedly carried by said support walls, c. a support means carried by said support walls, d. carriage means having opposed end portions pivotally carried on said first shaft between said end portions, one end portion of said carriage means resting on said support means, e. a second shaft rotatably carried by said carriage means in said one end portion and a bank of individual cams coupled to said second shaft, f. a counterweight carried by said carriage means at its other end portion, g. a third shaft carried by said spaced support walls, h. a bank of individual cam follower arms having opposed end portions each pivotally carried by said third shaft between said end portions, an end portion of each arm responsive to rotation of a cam of said bank of individual cams, i. welding tools carried by said follower arms at said end portion responsive to said cam means, j. spring means connected to said base member and the other end portion of each of said cam follower arms, k. a platen having opposed end portions pivotally carried by said third shaft between said end portions, one end portion in spaced relation with said welding tools, l. spring means connected to said base member and the other end portion of said platen, and m. actuator means engaging and pivoting said platen into working relationship with said welding tools.
 2. A material working machine according to claim 1 wherein said platen includes an electrode extending the length of said bank of individual welding electrodes.
 3. A welding machine according to claim 1 wherein said actuator means includes a roller means connected to said platen and movable ramp means engaging said roller, said roller rolling up said ramp means to move said platen. 